Watch The Live Stream of ISS Astronauts Trying to Fix The Ammonia Leak [Updating]

There’s an ammonia leak on the International Space Station, and at the time of this writing astronauts Christopher Cassidy and Tom Marshburn are on a spacewalk to fix it. So far they’ve reported there’s “no smoking gun” in terms of where the leak is coming from, but their suits feature cameras, so you can watch the whole thing streaming live, and that’s amazing. We’ll update throughout the day as more information develops.

Update 1: They’re replacing the “pump and flow subassembly box.” Chris Cassidy is currently bolting the new piece. When it’s done they will run ammonia through the new box and checking for leaks.

Update 2: It looks like NASA is guiding Cassidy and Marshburn through every step of the process, down to how many rotations of each bolt to make. It’s no doubt a delicate process, and they’re being very careful in this repair.

Update 3: Cassidy’s camera view just went blue and we’re looking at NASA. No one is saying anything about why.

Update 4: They’ve lost video because of “a handover” but everything is fine. They’re still in contact through audio channels.

Update 5 11:30 AM EDT: If the new “pump and flow subassembly box” works without leaking ammonia, NASA will likely determine the leak was from the old unit.

Update 6 11:37 AM EDT: Coming up on three hours of the space walk. The next step is to put the presumed failed pump and flow subassembly box in the spare slot.

Update 7 11:55 AM EDT: The new unit is in place, and so far there is no reported leakage of ammonia. This could mean the leak is fixed, but it doesn’t look like NASA or the crew are ready to call it. The crew is about one hour ahead of schedule.

Update 8 12:14 PM EDT: The crew has completed all of their tasks for the spacewalk. Before the new pump is turned on, the crew is moving to a safe distance where they can still monitor for any leaks.

Update 9 12:41 PM EDT: ISS Commander and real life Buzz Lightyear Chris Hadfield tweeted this with the order from NASA to run ammonia through the new pump:

Houston just sent the command to start flowing ammonia through the newly-installed pump. Gloved fingers crossed.

Update 10 12:52 PM EDT: The new assembly has been up and running for some time now with ammonia flowing. Currently no signs of any ammonia leaks. Cassidy and Marshburn have been on the spacewalk for four hours and nine minutes.

Update 11 1:06 PM EDT: The astronauts will be doing a “bake out” — sublimating any ammonia on their suits using the sun — for at least an hour before they head back into the ISS.

Update 12 1:21 PM EDT: The “bake out” is still ongoing, but ground control has given the okay for the astronauts to begin moving back towards the airlock.

Update 13 2:18 PM EDT: Looks like everyone’s back inside the ISS safely, and the leak appears to have been fixed. Congratulations to everyone on the ground and in space that made this happen. It’s amazing that they’re up there at all, but the fact that they can put on a suit, go outside, and make a repair like this is truly incredible.